Telephone system



c. E. LOMAX El AL 2,121,159

TELEPHONE SYSTEM Filed Nov. 23, 1936 June 21, 1938.

4 Sheets-Shet l INVENTOR. CLARENCE E.LOMAX JOHN H. voss ATTORNEY.

June 21, 1938.. c. E. LOMAX El AL 2,121,159

TELEPHONE SYSTEM Filed Nov. 23. 1936 4 Sheets-Sheet 2 INVENTOR. g CLARENCE E. LOMAX BY JQHN H. VOSS ATTORNEY.

June 21, 1938. c. E. LOMAX ET, AL 2,121,159

' TELEPHONE SYSTEM Filed Nbv. 25, 1936 4 Sheets-Sheet s FIG. 3

' INVENTOR.

CLARENCE E. LOMAX BY 5 JOHN H. VOSS ATTORNEY.

une EH, 1938; c; E. LOMAX ET AL TELEPHONE S YSTEM Filed Nov. 25, 1936 4 Sheets-$heet 4 mmozmw 0200mm 2 W5 S ww W MHH o v cN n E J 2C Patented June 21, 1938 UNITED PATENT Downers Grove, 1111.,

assignors to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application November 23, 1936, Serial No. 112,194)

28 Claims.

, The present invention relates in general to telephone systems in which connections may be established through the medium of subscriber controlled selector and connector switches, but is more particularly concerned with a system, of the above character which is combined with or has superimposed on it, so to speak, a fire alarm system; and the object of the invention may be. said to be, broadly, the provision of new and improved auxiliary. apparatus for use in connection with a telephone system.

In the preferred embodiment of the invention, means are, provided whereby any telephone in thesystem may be used as a fire alarm station in addition toperforming the functions usually ascribed to a telephone in an automatic system. When used as a fire alarm station the receiver ota given telephoneis removed and a certain digit dialled in the usual manner, the receiver then being immediately restored to the switch hook; As a result of theforegoing a code representative of the location of the originating telephone is sounded upon an alarm circuit, and a permanent record is made thereof.

A feature of theinvention relates to the employmentof a finder switch as a means of associatingany one of plurality of .fire alarm startionswith the fire alarm transmitting equipment, thereby making the system more reliable and zcheaperwto install and maintain.

These and other objects and features, not

specifically pointedout, will be apparent by referiring to the accompanying drawings which together with the detailed description constitute the preferred embodiment of the invention.

The drawings comprising Figs. 1 to 4, inclusive, when arranged with Fig. 1 to the left of Fig. 4, with Fig. 2 below Fig. 4 and with Fig. 3 to the left of Fig. 2, show sufiicientdetail to enable a clear understanding of this invention. In Fig. 1 is shown the automatic telephone stations A and A, which have the usual talking, signallingand impulse sending instrumentalities. The line switches C and C are mechanically of .-.the well known rotarytype in which the wipers have no normal position and move in a forward direction only.

, The selector switch E is mechanically of the wellknown vertical and rotary type in which the bank contacts are arranged in horizontal rows or levels. The connector switch denoted by the dotted rectangle H is alsoa switch of the vertical androtary type.

, The .holding bridge D is one of av number of .such bridges which are seizableby the selector E when the wipers of the said selector are raised to the ninth level of bank contacts. When a connection is extended to the holding bridge D, battery is supplied tothe calling subscriber by the line relay 1 l1, while a holding ground is provided by release relay 191.

A fire alarm relay, such as the relays R and R, is associated with each line switch in order that the telephone connected thereto may function as a fire alarm transmitting station.

In Fig. 2 is shown the finderswitch FS- which is of the vertical and rotary type having wipers 212 to 211, inclusive, which are moved first in a vertical direction and then in a rotary direction to find an operated fire alarm relay, such as the relay R of Fig. 1. Since, in the present embodimentof this invention, a finder switch of 200 point capacity is used, the finder FS is provided with two sets of wipers, the wipers 212, 2H1, and 216 forming the first set and wipers 213, 2 i5, and 211 forming the second set. The finder switch FS is also equipped with a vertical test wiper 262. Switching relayszlil and 2155 are of the type disclosed in Patent1,6'l3,884, issued June 19, 1928 to H. E. Pye. The cores of these switching relays are provided with two windings which are separated by a magnetic spacing member, a projection of which extends back and forms a back stop against which the armature of the relay rests. The winding .on the heel end of the relay is the magnetizing coil, and the fiux produced thereby traverses the path including this magnetic iron back stop, which is in shunt with the air gap, and no amount of current in this magnetic coil will cause the armature to operate. A very small current in the armature end winding of the relay, when in the same direction as the magnetizing winding, will cause the relay to operate. All relays of this type have been shown in the drawings with lugs extending from their center portion and such relays hereinafter will be referred to as three pole relays.

As the finder switch FS is of only 200 point capacityit follows that a plurality of such finders must be provided in order that access may be hadto all of the firealarm relays, such as relay R of Fig. l.

In Fig. 3 is shown a finder sequence switch SEQ-3 which functions to permit the operation of only one finder switch at a time. The sequence switch SEQ-3 isemechanically similar to the well known rotary line switch.

In Fig. .4 is shown a sender switch SEN-I which functions to transmit a three digit fire alarm code, distinctive of a particular telephone establishing a holding circuit for the line switch station, over the alarm circuit AC. A permanent record of the code is made by the conventional punch register PR.

The sender sequence switch SEQ2 functions to control the number of repetitions of the code and thereafter to release the initialing equipment.

The cross connecting frame CF provides means whereby the marker bank contacts, which are multiplied to all finder switches such as FS of Fig. 2 may be cross connected to the marker banks of the sender switch SEN-I.

The sender switch SENI and the sequence switch SEQ-2 are mechanically similar to the well known rotary line switch.

Operation 09 telephone system The system having been described in general, a detailed description will now be given of its operation, and for this purpose it will be assumed that the subscriber at station A, Fig. 1, desires to call station A whose number is assumed to be 236.

When the receiver is removed at the calling station, a circuit is closed over the line conductors III and II 2 for the line relay II3 of the line switch C. Line relay I I3, upon energizing, closes at armature II4 a circuit for switching relay I I5 and operating magnet I I6 in series, and at armature IIl connects the test wiper I to a point in the circuit between the switching relay H5 and the stepping magnet II6. From this point the operation depends upon whether the trunk line upon which the wipers of the line switch are standing is busy or idle. If it is busy there is ground potential on test contact I23, switching relay I I5 is thereby short circuited, and operating magnet II6, which interrupts its own circuit, is operated in the manner of a buzzer to advance the switch wipers step by step in search of an idle trunk. In the present case, however, we shall assume that the trunk upon which the wipers of the line switch are standing is idle. That being the case switching relay I I5 is not short circuited, and operating magnet I I 6 is not energized on account of the high resistance of switching relay II5. Switching relay II5, however, is energized and at armature I29 disconnects test wiper I20 from the point between its own winding and that of the operating magnet I I6 and connects it to the grounded private normal conductor I30. Relay II5 also disconnects the line conductors III and I I2 from the winding of relay H3 and ground respectively, and extends them by way of armatures I3I and I32 and their respective make contacts, wipers H8 and I2I, bank contacts I09 and I24, trunk conductors I and I28, armatures I33 and I34 and their break contacts, to the upper and lower windings of the line relay I35 of the selector E. Line relay I35 now energizes over the calling subscribers loop and at its armature I36 closes a circuit for the slow acting release relay I31 from ground at armature I45. Release relay I3I, upon energizing, opens a point in the circuit of release magnet I38, prepares a circuit for relay I39 at armature I40, and at armature I4I places ground upon release trunk conductor I 42, thereby C. By means of this ground potential on test contact I23 and its multiples in the banks of the other line switches which have access to selector E, the seized trunk is maintained busy in the usual manner. A branch of'this holding circuit extends by way of private normal conductor I30, to multiple test contacts in the banks of the connector switches having access to the calling line, thereby guarding it against intrusion in the usual manner. It may be mentioned that a further result of the energization of switching relay I I5 was the extension of the fire alarm conductor I26 to fire alarm relay R by way of armature I45 and its make contact.

The calling subscriber now operates his calling device in accordance with the first digit 2 of the desired number thereby producing two interruptions in the circuit of line relay I35 of the first selector E. As soon as relay I 35 deenergizes in response to the first of these interruptions a circuit is closed from ground at armature I46, armature I36 and its break contact, armature I and its make contact, through the series relay I39 and vertical magnet M1 to battery. Vertical magnet I41, upon energizing, raises the wipers I48, I49, and I 50 to a position opposite the first level of bank contacts, whereupon the off normal springs I52 close and complete a circuit from the grounded release trunk conductor I42, by way of armature I51 and its make contact, (relay I39 having energized), off normal springs I52, armature I58 and its break contact, through relay I53 to battery. Stepping relay I53, upon energizing, closes a point in the circuit of rotary magnet I54 at armature I55 and at armature I56 closes a locking circuit for itself independent of relay I39. When line relay I35 deenergizes inresponse to the second interruption produced in its circuit the vertical magnet M1 is again operated to raise the wipers one step, thus bringing the wipers opposite the desired level of bank contacts. Relay I39, being slow acting, will remain energized while impulses are passing through it to the vertical magnet. Shortly after the last vertical impulse relay I 39 will deenergize and close a circuit through the rotary magnet I54 at armature I51. Rotary magnet I54, upon energizing, advances the wipers I48, I49, and I50 into engagement with the first set of contacts in the second level, and at armature I58 opens the circuit of stepping relay I 53. Stepping relay I53, upon deenergizing, opens another point in its circuit, and at armature I55 opens the circuit of rotary magnet I54. Rotary magnet I54, upon deenergizing, again prepares the circuit of stepping relay I53. From this point the operation depends upon whether the trunk terminating in the first set of contacts is busy or idle. If it is busy, the stepping relay I53 energizes again over the following circuit; from ground by way of the test contact with which test wiper I49 is in engagement, test wiper I49, armature I6I and its break contact, off normal springs I52, armature I58 and its break contact, through relay I53 to battery. Stepping relay I53, upon energizing, closes a locking circuit for itself at armature I56 and at armature I55 again completes the circuit of rotary magnet I54. This alternate operation of the stepping relay I53 and the rotary magnet continues so long as test wiper I49 engages grounded contacts. In this case we will assume that the trunk line comprising conductors I01, I98, and I99 is the first found to be idle. That being the case, when the wipers of selector E arrive upon bank contacts I62, I 63 and 1 I64 there is no ground on test contact I63 and consequently stepping relay I53 does not again energize. With this condition existing switching relay I59 energizes over the following circuit; from ground by way of release conductor I42, switching relay I 59, off normal springs I 52, armature I58 and its break contact, through relay I53 to battery. Stepping relay I 53 does not energize over this circuit on account of the high resistance of switching relay I59. Relay I59, upon aim-gran energizing, removes ground 'fromthe 1 circuit of relay I31 at armature: I 46, disconnects test wiper I49 from the point between switchingrelay I59 andstepping relay I53 and connects it to'ground byway of release trunk conductor I42 at arma- I31. ofthe selector E has had timeto deenergize.

When'the calling subscriber operates his callingdevicein accordance with thesecond digit 3 of thedesired number, the connector H will raise its wipers to a position oppositefthe third'levelof bank contacts. ,The calling subscriber now dials thefinal digit 6 of the desired number, .where: upon the connector rotates its wipers six steps intoconnection' with the line extending to the station A. Upon the, completion of the :connec- ,tion to the called linea signalling circuit is es- An explanation will now be given of [the fire alarm transmitting equipment. The "subscriber, when wishing to originate afirealarm at station i A, will first removethe receiver, whereupon the line switch C will operate in theusual manner to extend the connection to a first selector,it being assumedthat the selector E is the one first found tote idle. The subscriber next dials the digit 9, and as a result thereof theselector E raises the wipers I48, I49, and I50 to a position opposite the ninth level of bank contacts." The selector next selects an idle trunk in thislevel, and it will'be assumed thatthe trunk comprisingconductors I81, I88, and I89 is the one first found to beidle. The switching relay I59 of the selector E, upon energizing, disconnects the trunk conductor I25 and I28 from line relay I35 and extends them by wayofmake contacts ofarrnatures' I33 and I34, wipersl48 and I59, bank contacts I92 and I93,

conductors" I89 and I81, through the double wound relay 19 0 of the holding bridge 1),- to battery and ground, respectively. The line relay I99,upon energizing, closes the circuit of release relay I9 I at armature I13, and the latter relay,

upon energizing, places ground upon the release trunk conductor I88 at armature I14, thereby establishing the usual'holding circuit for the selector E andtheline switch C. A further result of the energizationbf relay I9I is the closing of a circuit fromgfound at armature I15, break contact and-armature I16; through relay I11 to battery. Relay l11, upon energizing, opensits own' circuit and will thereforepperateas a buzzer as long as armature I15 remains operated. This buzzer action of relay I11 produces atonewhich isplaced on the negative line byway of condenser I18 and conductor l81.- Y Thifs tone is audible in the receiver-at substation A-and advises the-subscriber thatfthe desired fire alarmwhasflbeen initiated. The sub:- scriber thenrestores his receiver, whereupon the releaseof the switches involved in this connection'takes place in the usual manner;

Returningto a "consideration of selector E at the timeof the energization of switching relay I59; the above mentioned operation results in the'deenergization of line relay I35 followed after a time bylthe release of the slowactingrelease relay I31 During the interval of time elapsing between the energization of relay I59 and the deenergization of relay I31 a circuit may be traced as follows: from ground at armature I46 and its make contact, armature HI and its make contact, springs I 12 which are closed by the shaft only when raised to the ninth level, conductor I20, bank contact I22, wiper II9,make contact and armature I45, through fire alarm relay R and resistance I82 to battery. i

. Firealarm transmission From the foregoingdiscussion it is apparent that thefire alarm'system comprises a plurality offirealarm relays, such as relay R of Fig. 1, and thatmore than oneof said relays may be energized simultaneously.

The firealarm transmitting apparatus conassociated sequenceswitchSEQ-Ai.

In order that the single fire alarm sender may become associated with one of a plurality of fire alarm relays, ithas been necessary to introduce. a findersystem comprising a plurality of finder switches suchas FS oi Fig. 2.

'sistsof the single sender SENI of Fig. 4, and the hundred 'firealarm relays, it follows then that the purpose of the finder sequence switch SEQ- 3 is topermit but one finder tooperate at a'time and thereby associate, for the time being, one fire alarm relay with the common fire alarm sender.

For the purposeof explanationwef will assume that station Aof Fig. 1 has been assigned the number 222, and that finder switch E8 of Fig. 2 serves the first andsecond hundred lines. Mention may bemade here that the various fii'lders are associated in order with the bank contacts of thefinder sequence switch SEQ.-3, and that each contact in the bank accessible to wiper 302 (the finder bank) is normally grounded through break springs on the start relay of the particular finder associated therewith.

Returning now to a consideration of the previously described energizationof relayR of Fig. 1,

we-find that acircuit may be traced from ground at' armature I8I, conductor 200, resistance 20I (common to 29 relays such as relay R) through start relay 202 to battery (the latter relay is common to 200 relays such as relay R). Relay 202, upon energizing, removes ground, at armature 203;from the contact associated with finder F8 in 9 I As previously stated, each finder switchhas access to onlytwo iBI) the finder bank-of the finder sequence switch SEQ3.'

A further result of the energization of'start relay 202 is the placing of ground onthe common kick oif circuit of sender sequence switch SEQ-+3,

the circuit may betraced from ground'at armature 293 and its make contact, conductor 300,

normal bank contact 30 I wiper 302, armature 303 and its break contact, through self interrupting springs and operating magnet 304 to battery. The operating magnet 304 will now energizaopen its own circuit, anddeenergize to advance wipers 302, 324, 3I6, and 329 into: engagement with the first contact in the banks associated therewith.

The operationknow depends uponwhether'the start relay of the first finder switch is energized or not. If it is not energized a circuit may be traced from ground at armature 203 and its break contact, break contact and off normal spring 204, break contact and armature 205, conductor 305, bank contact 306, wiper 302, armature 303, through self interrupting springs and operating magnet 304 to battery. The operating magnet will now energize and act as a buzzer to advance the wipers of the sender sequence switch step by step so long as wiper 302 engages grounded bank contacts.

In the present case we have shown start relay 202 to be energized at the time that wiper 302 engaged bank contact 306, and it follows that there will be no further rotation at this time.

A further result of the energization. of start relay 202 is the closing of a circuit from ground at armature 206 and its make contact, conductor 301, through relay 308 to battery. Relay 308 will now energize and light the busy lamp 309, and will also close a circuit from ground at armature 310 and its make contact, make contact and armature 3| I, relay 312, through self interrupting springs and operating magnet 304 to battery. The operating magnet will not energize at this time because of the high resistance of relay 312.

Relay 312 will now energize and prepare a circuit for the operating magnet 304 at armature 303; provide a locking circuit for itself at armature 320; prepare a circuit for the lower winding of relay 321 at armature 322; and close a circuit from ground at armature 323, wiper 324, bank contact 325, conductor 326, through relay 220 to negative battery. Relay 220 will now energize and close the polarizing circuit of the three-pole relays 218 and 219 at armature 221, this, as previously explained, will not cause the operation of said relays.

A further result of the energization of relay 312 is the closing of a circuit from ground at armature 313, break springs controlled by armature 314, armature 315 and its break contact, wiper 316, break contact 311, conductor 201, through vertical magnet 208 to battery. The vertical magnet will now energize and raise test wiper 262 and wipers 212 to 211, inclusive, to a position opposite the first level of bank contacts; at the same time closing a circuit from ground at armature 209, conductor 318, through relay 319 to negative battery. Relay 319, upon energizing,

will open the circuit to the vertical magnet 208 at break contacts controlled by armature 314, whereupon the vertical magnet deenergizes and at armature 209 opens the circuit to relay 319. The deenergization of relay 319 again closes the circuit of the vertical magnet 208, whereupon the Wipers of the finder are advanced another vertical step. This interaction between the vertical magnet 208 and relay 319 takes place in the manner just described until thetest wiper 262 of the finder FS finds marking ground applied to a vertical bank contact.

As previously explained, the second Vertical bank contact is grounded by relay R of Fig. l, and when that contact is engaged by wiper 262, ground thereon is extended by said Wiper, conductor 321, bank contact 328, wiper 329, armature 330 and its break contact, lower winding of relay 321, make contact and armature 322, through relay 319 to battery. It follows then that relay 319 will not deenergize when its circuit is opened by the subsequent deenergization of the vertical magnet 208, thus the vertical stepping ceases. Relay 321 will now energize sufliciently to lock its upper winding, by way of make contact and armature 331 to ground at armature 313; the circuit of its lower winding, and of relay 319, will be opened at armature 330 when the relay becomes fully operated as the result of the energization of its upper windings.

A further result of the energization of relay 321 and the deenergization of relay 319, is the closure of a circuit from ground at armature 313, break contacts controlled by armature 314, armature 315, and its make contact, conductor 221, make contact and armature 222, break contact and armature 223, break contact and armature 224, through rotary magnet 225 to battery. Rotary magnet 225, upon energizing, rotates the wipers 212 to 211, inclusive, into engagement with the first set of bank contacts in the second level, and rotates the vertical test wiper 262 out of engagement with the vertical bank. At armature 226, rotary magnet 225 completes a circuit for relay 319 over conductor 318. At this point further rotation of the wipers of the finder switch FS is dependent upon whether the test wipers 216 and 211 encounter ground or not. In case ground is not on either of the bank contacts with which the test Wipers are in engagement, neither of the switching relays 218 or 219 will energize.

"Therefore, as the rotary magnet 225 causes the energization of relay 319, and the latter relay in turn opens the circuit of the rotary magnet, a cycle of operations is set up which results in the step-by-step operation of the rotary magnet until one of the test wipers 216 or 211 encounters a grounded bank contact.

Owing to the fact that fire alarm relay R (whose number assignment was assumed to be 222) is energized, test wiper 216 will find ground on the second bank contact in the second level. At that time a circuit for the three-pole switching relay 218 may be traced from ground at armature and its make contact, conductor 229, bank contact 230, test wiper 216, through the operating Winding of switching relay 218 to negative battery at make contact and armature 228. The current now flowing through the operating winding of switching relay 218 is in a direction to assist that flowing through the polarizedwinding, and, as a result, the switching relay energizes very quickly to open the circuit of rotary magnet 225 at armature 224.

A further function of switching relay 218 is to establish marking points in the banks of the sender switch SEN1 so that the code 222 distinctive of telephone station A, will be retransmitted over the alarm circuit AC. In accordance with the assumption that finder switch FS serves the first and second hundred lines, armature 231 of relay 218 has been connected by way of conductor 236 and jumper 432 of cross connecting frame CF to bank contact 431 in the bank served by wiper 401, thereby establishing 2 as the hundreds digit of the code. To digress for a moment, it may be said that, had the finder FS searched for and found the fire alarm relay associated with telephone station 122, the physical movement of its Wipers would have been the same as that previously described, but in the latter case relay 219, instead of relay 218 would have energized. Therefore the make contact of armature 232 of relay 219 has been connected by way of conductor 235 and jumper 465 of cross connecting frame CF to bank contact 466 in the bank served by wiper 401, thereby establishing l as the hundreds digit of the code. The tens and units digits being the same for corresponding numbersin each hundred, itfollows that bank contact 233 mayl be cross connected to establish the units digitof the code and thatb'ank, contact 234 may be cross connected toestablish the tens digit of the code. Therefore bank contact 233 has been connectedby way of conductor 239 and jumper 445 of cross connecting frame CF to bank contact 444 in the bank served by wiper 441. Bank contact 234.has:been connected by way of conductor 231.,and jumper 442 of cross connecting frame CF to. bank contact 44! in the bank served by wiper 401. v

v Relay 2 l8, upon energizing, closes a circuit from ground, through high resistance relay 48!, con"- ductor 400,ar'mature 243, and its make contact, make contact and armature 205, conductor 385, ban-k contact 306, wiper 332, armature 303 and itsmake contact through operating magnet 304 to battery. Theoperating magnet cannot energizeat this time because of the high resistance of relay .401. The last mentioned relay will, however, energizev and close a circuit from ground at armature 402 and its make contact, armature 403 and its'break contact, through relay 404 to negative battery. Relay 404, upon energizing, will close a circuit from ground at armature 405 andx-its make contact, make contact and armature 406, wiper 401, bankcontact 408, make contact anduarmature 409, through relay M0 and resistance! to battery. Relay 410 will now energize andqlo'ck itself up to ground at arma ture 405 by way of armature M2 and its make contact. Relay M0 also prepares the circuit of coding relay 428 at armature 421.

"A' further result of the energization of relay 404 is the closing of a start circuit to the interrupter relay group comprising relays 415, M8, Land 426,. the circuit may betraced from ground at armature 405 and its make contact,

armature M3 and its break contact, through relay 415 to battery. Relay 4I5 now energizes and at. armature M6 extends the start circuit to relay 4|,8. Relay 4I8'next energizes and at armature14l9 extends the start'circuit to relay 42!. Relay 42i thereupon energizes and, extends the start circuit by way of armature 422. and its make contact, armature 423 and its break contact, armature 425 and its break contact, through relay 426 tobattery. Relay 428 will now energize andopen-the circuit of relay 4i 5 at armature 4l3. Relay 4l5 will nextdeenergize and open thecircuit of relay 418 at armature 4H5. Relay 418 thereupon deenergizes and opens the circuit of, relay 421 at armature M8. Relay 42!. then deenergizes and opens the circuit of relay 426 at armature 422. Relay 428 finally deenergizes and again closes the circuit to relay M5 at armature 4l-3, whereupon the cycle is repeated and the interrupter continues to function so long as the start circuit is grounded by armature. 405.

At each energization of relay 42! a circuit, in parallel with armature 425 and relay 426, is closed through operating magnet 424 to negative battery, therefore wipers 441, 401, 438, and 461 are advanced step-by-step under control of theaforementioned interrupter relays; At each energization of relay 428 the grounded start circuit is extended byway of armature M3 and its make contact, make contact and armature 421, through coding relay 428 to battery. It follows then. that at each cycle of the aforementioned interrupter relays the coding relay 428 will energize and impress current from generator-G on the alarm circuit AC by way of armature 430 audits: make contact, thus causing the operationpf all ringers bridged across that circuit, such as ringer R. A further result of the energization of coding relay 428 is: the closing, at armature 429 and its make contact, of a circuit through the conventional punch register PR. I

At the second step of the. sender switch SEN-l the first marked contact is reached and a. circuit may be traced from ground at armature 405 and its make contact, make contact and armature 408, wiper. 401, bank contact 43L, jumper 432,

conductor 236, armature 231 andits make contact, break contact and armature 232, conductor 433, make contact and :armature'434, through relay 435 to negativebattery. As the wipers of the sender switch SEN--l advance upon the deenergization of the operating magnet 424 it follows that relay 435 will energize in time to prevent the further operation of the operating magnet 424 by the open circuit at armature 423. Furtheroperation of relay 426wil1 be prevented by the open circuit at armature 425. A circuit is also closed from ground at armature 436, armature 431and itsmake contact, through resistance 44! to battery. The latter traced circuit serves to shunt relay 4H), which will now deenergize and open the circuit to coding relay 428.

As a result of the foregoing operations it will be seen that the coding relay 428 has twice energized and thus impressed upon. the alarm circuit AC, and the punch register PR, the hundreds digit of the code 222, u 7

A further result of the energization. of relay 435 is the closure of a restoring circuit extending from ground at bank contact 438, wiper 438,

armature 439 and its make contact, through self interrupting springs and operating magnet 424 to battery. It is further to be noted that relay 435 locks itself to this restoring circuitby way of armature 440 and its make contact. The operating magnet will now energize, open its own circuit, and continue to function as a buzzer to advance the associated wipers step by step so long as wiper 438 engages grounded contacts. When bank contact 440 is reached bywiper 438 the self interrupted rotation will cease, and shortly thereafter slow-to-release relay 435 will deenergize and again close the relayinterrupter circuit to the operating magnet 424 and to relay 426. The next pulse to the operating magnet 424 will cause wiper 401 to advance into. engagement with bank contact 489, at which time the circuit of relay M0 in series with resistance 4 will again be closed, with the result that the latter relay will energize, lock up to ground on the start conductor and again prepare the circuit of coding relay 428. The time interval introduced by the circuit operations just described provides the required interval between the transmission of the first and second digits of the code'222..

. Subsequent cycles of the interrupter will cause the advancement of the wipers of the sender switch SEN--l and the further operation of coding relay 428. The second marking point will be reached when wiper 401 engages bank contact 44!, thereby completing a circuit to relay 435 by way of jumper 442, conductor 231., bank contact 2 34, wiper 2l3, make contact and armature 238, conductor 433, and make contact and armacode 222. When bank contact 443 is reached by wiper 438 the self interrupted rotation will cease, relay 435 will deenergize and again close the relay interrupter circuit to the operating magnet 424, and to relay 426. The next pulse to the operating magnet will cause wiper 441 to advance into engagement with bank contact 410, at which time the circuit of relay 4| 0 in series with resistance 4 will again be closed, with the result that the latter relay will energize, lock up to ground on the start conductor and again prepare the circuit of coding relay 428. The time interval introduced by the circuit operations just described provides: the required interval between the transmission of the second and third digits of the code 222.

Subsequently cycles of the interrupter'will cause the advancement of the wipers of the second switch SEN-l and the further operation of coding relay 428. The third marking point will be reached when wiper 441 engages bank contact 444, thereby completing a circuit to relay 435 by way of jumper 445, conductor 239, bank contact 233, wiper 2l2, make contact and armature 240, conductor 433 and armature 434. Relay 435 will'function as before to stop the interrupter, to shunt relay M0, and to close the restoring circuit of operating magnet 424. As a result of the foregoing, it will be seen that the coding relay 428 has twice energized and thus impressed upon the alarm circuit AC, and the punch register PR, the units digit of the code 222. When bank contact 411 is reached by wiper 461 the self interrupted rotation will cease, relay 435 will deenergize and again close the relay interrupter circuit to operate magnet 424 and to relay 426. The wipers of the sender switch SEN-| will continue to advancein response to the operation of the relay interrupter, and as wiper 441 passes over bank contact 446 a pulse of current is passed to the operating magnet 448 of the sender sequence switch SEQ-2. The latter magnet will respond thereto and advance wipers 453 and 454 one step, but without effect at this time. The time interval'introduced by the circuit operations just described provides the required interval between the first and second rounds, or repeats, of the code 222.

When wiper 401 of the sender SENI next engages bank contact 408 the circuit will again be closed to relay M0, and thus will start the transmission of the second and final round of the code 222. This operation need not be described in detail, as it is merely a repetition of what has gone before, and it will suffice to point out that the next pulse of current by way of wiper 441 and bank contact 446 will cause the operating magnet 448 of the finder sequence switch SEQ-2 to advance the associated wipers one step. A circuit is now closed from ground at wiper .454, bank contact 455, through relay 456 to battery. Relay 456, upon energizing, closes a circuit from ground at armature 46! and its make contact, conductor 462, armature 242 and its break contact, make contact armature 24!, wiper 2K4, bank contact 299, conductor I83, through resistance I82 to battery. The foregoing circuit is in shunt of fire alarm relay R and results in the deenergization of said relay; thereby positive potential marking is removed from bank contacts 230 and 249, and the circuit to start relay 202 is opened. Start relay 202 now deenergizes and opens the circuit of relay 308 which, in turn, deenergizes and extinguishes the lamp 309;

A further result of the energization of relay 456 is the shunting of relay at armature 460, thereby causing the complete energization of operating magnet 304 of finder sequence switch SEQ3. Operating magnet 304 will open the circuit of relay 3l2 at the self interrupting contacts of said operating magnet, whereupon relay 312 will deenergize and, by virtue of armature 303, will transfer wiper 302 from the terminal of the operating magnet 304 to the break spring of self interrupting contact associated with the said operating magnet. The operating magnet 304 will now deenergize and advance the associated wipers one step and, upon the assumption that no other fire alarm relay, connected to the relay R of Fig. 1, is energized at this time, wiper 302 will engage grounded bank contacts and operating magnet 304 will function as a buzzer to advance the associated wipers step by step to the normal position shown in Fig. 3. A further result of the deenergization of relay M2 is the opening of the locking circuit of relay 32l, whereupon the latter relay deenergizes. The sender sequence switch SEQ3 is now in normal position and awaits the next energization of a fire alarm relay.

The deenergization of relay 3I2 and the subsequent advancement of the sender sequence switch wipers will result in the deenergization of relay 220 of the finder switch FS, whereupon the circuit to the polarizing winding of relays 2| 8 and 2|9 is opened at armature 221, and the battery feed to the operating winding of the same relays is opened at armature 228. Relay 2| 8 now deenergizes. A further result of the deenergization of relay 220 is the closing of a circuit from ground at armature 221 and its break contact, off normal spring 244 and its make contact, armature 245 and its break contact, break contact and armature 2248, release magnet 241 in parallel with resistance 248, conductor 332, through relay 333 to battery. Relay 333 will energize and close the circuit of lamp 334, and at the same time the release magnet 241 will energize and cause the shaft and wipers 2I2 to 2| 1, inclusive, and test wiper 262 to return to normal position, its own circuit being opened when the shaft reaches normal position because of the off normal springs ONS. The finder switch FS is now in normal position and awaits the next seizure by the sender sequence switch SEQ-3.

It may be mentioned in passing that the release of the finder switch FS would occur as described even though one or more fire alarm relays associated therewith might be energized at the time that relay R of Fig. 1 deenergizes. The springs indicated at reference 250 are actuated by the shaft only in the event that eleven rotary steps are taken. The advance of the sender sequence switch SEQ-4 and the release of the finder switch FS would occur as the result of such an unstandard operation.

Returning now to a consideration of the sender sequence switch SEQ-2, it will be seen that relay 40I, upon deenergizing, opens the circuit of relay 494 which, in turn, deenergizes and removes ground from the relay interrupter start circuit at armature 405, and at the break contact of the same armature completes a restoring circuit by way of bank contact now engaged by wiper 461, said Wiper, break contact and armature 434, through relay 435 to battery. Relay 435 will now operate and extend its energizing circuit by way of armature 439 and its make contact, through self interrupting springs and motor magnet 424 to battery. The operating magnet will now energize, interruptits own circuit, and function as a buzzer to advance the associated wipers step by step so long as wiper 461 engages grounded bank contacts. When wiper 438 engages bank contact 413 the rotation will cease, shortly thereafter relay 435 will deenergize and the sender will again be in normal position awaiting the next seizure by a finder switch such as the finder switch FS of Fig. 2.

A still further result of the energization of relay 456 is the closing of a circuit from ground at armature 449 and its make contact, high resistance 450, relay 45!, in parallel with resistance 452, bank contact 412, wiper 453, throughself interrupting contact and operating magnet 448 to battery. The operating magnet 448 will not energize at this time because of the high resistance 450,: relay 45! will, however, energize and provide a locking circuit for relay $58 at armature 458. A further function of relay MI is to shunt resistance 50 at armature 451, whereupon the operating magnet 448 will energize in series with relay 45l, will open its own circuit, and operate as a buzzer to advance the associated wipers step by step so long as wiper 453 engages contacts multipled to relay L When wiper s53 engages bank contact 463 the rotation will cease, and shortly thereafter relay i5l will deenergize and open the locking circuit of relay 456. It may be mentioned here that bank contact 463 is only one of the five normal positions which may be assumed by wiper 453.

Key-K-4 and relay 464 provide means whereby a second sender, whose marker banks are in multiple with those of sender SENI, may be placed in service inthe event of the failure of sender SEN-4.

While the invention has been shown as a combined telephone and fire alarm system, it will be i understood that the signalling system could be utilized equally as well for other purposes, as for instance, messenger call, police signalling, a watchmans service.

The object and scope of this invention having been described, what is considered to be new and what is desired to have protected by Letters Patent, will be pointed out more specifically in the appended claims.

What is claimed is:

1. In a combined telephone and signalling system, a central exchange, a plurality of subscribers lines extending to said exchange, means included in said exchange and controlled over a calling one of said subscribers lines for establishing a telephone connection between said calling subscribers line and a called subscribers line, code transmitting equipment included in said exchange and comprising a pluralityof finder switches, an alarm relay associated with each of said subscribers lines, means controlled over any calling one of said subscribers lines for operating the alarm relay associated with the calling line, means responsive to the operation of said alarm relay for initiating the operation of said code transmitting equipment, an alarm circuit extending to said exchange, and means controlled by said code transmitting equipment for transmitting over said alarm circuit a code identifying the calling subscribers line.

2. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, means in said exchange and comprising a plurality of automatic switches for establishing telephone connec tions between said subscribers lines, code transmitting equipment in said exchange and comprising a pluralityof finder switches, means controlled over a calling one of said subscribers lines for establishing a connection between the calling line and said code transmitting equipment, said connection extending by way of at least a portion of said automatic switches, means individually associated with each of said I subscribers lines for causing said code transmitting equipment to generate a coded signal identifying the associated subscribers line, an alarm circuit extending to said exchange, and means controlled by said code transmitting equipment for transmitting over said alarm circuit acoded signal corresponding to any calling one of said lines.

3. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, means included insaid exchange and comprising a plurality of automatic switches for establishing telephone connections between said lines, code transmitting equipmentin said exchange and comprising a plurality of finder switches, holding means accessible to a portion of said automatic switches, means controllable over any one of said subscribers lines for initiating the operation of said holding means, means individually associated with each of said subscribers lines for'initiating the operation of said code transmitting equipment, means responsive to the operation of said holding means for causing the operation of said last-named means, and means responsive to the operation of said code transmitting equipmentfor transmitting a coded signal identifying the calling line. I v

i. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, means including a plurality of automatic switches for establishing telephone connections between said lines,

code transmitting equipment in said exchange and comprising a plurality of finder switches, means individually associated with each of said lines for initiating the operation of said code transmitting equipment, holding means accessible to said subscribers lines, means including a portion of said automatic switches for establishing a connection between a calling one of said lines and holding means and-for causing the operation of said holding means, and means responsive to the operation of said holding means for initiating the operation of said second-named means. i

5. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, means comprising a plurality of automatic switches for establishing telephone connections between said lines, code transmitting equipment in said exchange, relays individually associated with said subscribers lines and each operative to initiate the operation of said code transmitting equipment, each of said relays being operative to mark the associated line in one of said finder switches, whereby said code transmitting equipment is rendered operative to transmit a coded signal identifying the said associated line, and means in-. cluding said automatic switches for causing the operation of said relays.

6. In a signalling system, a plurality of lines each identified by a certain code designation, a

plurality of control means, a series of selecting switches controllable over any one of said lines to select an idle one of said control means, code transmitting equipment, finder switches includ 13. In a combined signalling and telephone system, a central exchange, automatic switches in said exchange, a plurality of lines extending to said exchange and terminating in said automatic switches, code signalling equipment in said exchange, finder switches included in said" code signalling equipment, means controlled over any calling one of said lines for causing the operation of said automatic switches to establish a telephone connection between the calling line and a called one of said lines, means controlled over any calling one of said lines for causing said automatic switches to establish a connection between the calling line and said signalling equipment, means in said equipment and responsive to the connection of any calling line therewith for generating a code individual identifying the calling line, and means for transmitting said code from said exchange.

14. In a combined telephone and signalling system, a central exchange, "automatic switches in said exchange, a plurality of substation lines extending to said exchange and terminating in said automatic switches, substations connected to said lines, code signalling equipment in said central exchange, finder switches included in said code signalling equipment, means controlled from a calling one of said substations for operating the automatic switches to establish a telephone connection between the calling substation and a called substation, said means being operative to control the automatic switches in accordance with a predetermined number to establish a connection between the calling substation and said signalling equipment, means in said signalling equipment and responsive to the connection of a substation therewith for generating a signal identifying the calling substation, and means operative to transmit said signal from said exchange regardless of whether the calling substation has been released from its connection with the signalling equipment.

15. In a combined telephone and signalling system, a central exchange, a plurality of substations connected to said exchange, code signalling equipment in said exchange, finder switches includedin said code signalling equipment, means in said exchange controlled from a calling substation for establishing a telephone connection between the calling substation and any desired called substation, said means being controllable from any calling substation to establish a connection between the calling substation and said signalling equipment, means for transmitting a signal to the calling substation when such signalling connection is established whereby the connection may be immediately released at the calling substation, means included in said signalling equipment and responsive to the connection of a calling substation therewith for generating a signal identifying the calling substation, and means for then transmitting said lastnamed signal independently of the continued connection of the calling substation with said equipment. p

16. In a combined telephone and signalling system, a central exchange, substations connected to said exchange and each including an impulse sender, code signalling equipment at said exchange, finder switches included in said signalling equipment, means responsive to the operation of the impulse sender at a calling substation in accordance with the designation of a called substation for establishing a telephone connection between the calling and called substations, means responsive to the operation of the impulse sender at a calling station in accordance with a predetermined designation for establishing a connection between the calling substation and said signalling equipment, means included in said signalling equipment and responsive to the connection of a substation there for generating a signal identifying the calling substation, means for indicating to the calling substation that the connection with the signalling equipment is established so that the connection may be released if desired, and means in said signalling equipment for transmitting the signal identifying the calling substation from said central exchange.

17. In a combined telephone and signaling system, a central exchange, substation lines extending to said exchange, a series of automatic switches in said exchange controllable over said substation lines to establish telephone connections between the substation lines, code signal .ling equipment in said exchange, means for controlling the automatic switches over any calling one of said lines to establish a connection be-- i tween the calling line and said signalling equipcluded in said code signalling equipment, a circuit connection extending from the terminating end of each substation line to said signalling equipment, means for controlling the automatic switch over any calling substation line to extend a connection from said calling line to said signalling equipment, means responsive to the establishing of said last-named connection for energizing said circuit connection to initiate the operation of said signaling equipment to generate a signal identifying the calling line, and means in said signalling equipment and including one of said finder switches for transmitting said code.

19. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, said lines being arranged in groups, means including a plurality of automatic switches located in said exchange for establishing telephone connections between said lines, each of said switches being operable to a plurality of positions, a plurality of auxiliary automatic switches, each of said auxiliary switches corresponding to a particular group of said lines and each having a plurality of positions individually corresponding to the individual lines of the corresponding group, means responsive tothe operation of one of said firstnamed plurality of switches to a predetermined position for selecting a predetermined one of said auxiliary switches and for causing the se lected switch to operate to a predetermined one of its said positions, a signal transmitter adapted to transmit signals of different characteristics individually corresponding to the various positions of each of said auxiliary switches, and means responsive to the operation of any one of said. auxiliary switches to any one of its said positions for causing said code transmitter to transmit the signal corresponding to the said one position.

20. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, said lines being arranged in groups, means including a plurality of automatic switches for establishing telephone connections between said lines, each of said switches being adapted to be taken for use by a calling one of said lines and being operative to a plurality of positions, a plurality of auxiliary automatic switches, each of said auxiliary switches corresponding to a particular group of said lines and each having a plurality of positions individually corresponding to the individual lines of the corresponding group, means comprising a selector switch commonly associated with all of said lines and responsive to the operation of one of said first-named plurality of switches to a predetermined position for selecting the one of said auxiliary switches which corresponds to the calling line responsible for the operation of said one of said first-named switches, means responsive to the selection of said one auxiliary switch for causing the operation thereof to a predetermined position corresponding to the last-named calling line, a signal transmitter adapted to transmit signals of different characteristics individually corresponding to the positions of each of said auxiliary switches, and means responsive to the operation of said one auxiliary switch to said predetermined position for causing said code transmitter to transmit the signal corresponding to the said predetermined position.

21. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, said lines being arranged in groups, means including a plurality of automatic switches for establishing telephone connections between said lines, each of said switches being adapted to be taken for use by a calling one of said lines and being operative to a plurality of positions, holding means arranged to be operated in response to the operation of any one of certain of said switches to a predetermined position, a plurality of auxiliary automatic switches, each of said auxiliary switches corresponding to a particular group of said lines and each having a plurality of positions individually corresponding to the individual lines of the corresponding group, means comprising a selector switch commonly associated with all of said lines and responsive to the operation of said holding means for selecting the one of said auxiliary switches which corresponds to the calling line responsible for the operation of said holding means, means responsive to the selection of said one auxiliary switch for causing the operation thereof to a predetermined position corresponding to the last-named calling line, a signal transmitter adapted to transmit signals of different characteristics individually corresponding to the positions of each of said auxiliary switches, and means responsive to the operation of said one auxiliary switch to said predetermined position for causing said code transmitter to transmit the signal corresponding to the said predetermined position.

22. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, said lines being arranged in groups, means including a plurality of automatic switches for establishing telephone connections between said lines, each of said switches being adapted to be taken for use by a calling one of said lines and being operative to a plurality of positions, holding means arranged to be operated in response to the operation of any one of certain of said switches to a predetermined position, a relay individually. associated with each of said lines and operative in response to the operation of said holding means only when the associated line is the calling line responsible for the operation of said holding means, a plurality of auxiliary automatic switches, each of said auxiliary switches corresponding to a particular group of said lines and each having a plurality of positions individually corresponding to the individual lines of the corresponding group, means comprising a selector switch commonly associated with all of said lines and responsive to the operation of any one of said relays for selecting the one of said auxiliary switches which corresponds to the group of lines including the line with which said one relay is associated, means responsive to the selection of said one auxiliary switch for causing the operation thereof to a position corresponding to the line associated with said one relay, a signal transmitter adapted to transmit signals of difierent characteristics individually corresponding to the positions of each of said auxiliary switches, and means responsive to the operation of said one auxiliary switch to said predetermined position for causing said code transmitter to transmit the signal corresponding to the said predetermined position.

23. In a combined telephone and signalling system, an exchange, a group of subscribers lines extending to said exchange, means including a plurality of automatic switches for establishing telephone connections between said lines, an auxiliary automatic switch having positions individually corresponding to individual ones of said lines, means responsive to the operation of one of said plurality of switches to a predetermined position for causing said auxiliary switch to operate to one of its said positions, a signal transmitter adapted to transmit coded signals of different characteristics individually corresponding to the various positions of said auxiliary switch, and means responsive to the operation of said auxiliary switch to one of its said predetermined positions for causing said transmitter to transmit the coded signal corresponding to the said position.

24. In a combined telephone and signalling system, an exchange, a group of subscribers lines extending to said exchange, means including a plurality of automatic switches for establishing telephone connections between said lines, an auxiliary automatic switch having positions individually corresponding to individual ones of said lines, holding means arranged to be operated in response to the operation of one of said plurality of switches to a predetermined position, means responsive to the operation of said holding means for causing said auxiliary switch to operate to one of its positions, a signal transmitter adapted to transmit coded signals of different characteristics individually corresponding to the various positions of said auxiliary switch, and means responsive to the operation of said auxiliary switch to one of its said predetermined positions for causing said transmitter to transmit the coded signal corresponding to the said position.

25. In a combined telephone and signalling system, an exchange, a group of subscribers lines extending to said exchange, means including a plurality of automatic switches for establishing telephone connections between said lines, each of said switches being arranged to be taken for use by a calling one of said lines and being operative to a plurality of positions, holding means arranged to be operated in response to the operation of one of said switches to a predetermined position, a relayindividually associated with each of said lines and operative in response to the operation of said'holding means only when the associated line is responsible for the operation of said holding means, an auxiliary automatic switch having positions individually corresponding to said relays, means responsive to the operation of one of said relays for causing said auxiliary switch to operate to the one position corresponding to said one relay, a signal transmitter adapted to transmit coded signals of different characteristics individually corresponding to the various positions of said auxiliary switch, and means responsive to the operation of said auxiliary switch to said one of its positions for causing said transmitter to transmit the switch to a predetermined position for operating said relay, and signalling means responsive to the operation of said relay for transmitting a signal identifying said one line.

2'7. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, a telephone including an impulsing device connected to one of said lines, an automatic switch adapted to be taken for use by said one line in response to the initiation of a call at said telephone, said switch being operable to a plurality of positions in response to impulses transmitted thereto from said impulsing device, holding means operative in response to the operation of said switch to a predetermined position, a relay associated with said one line and operative in response to the operation of said holding means, and signalling means responsive to the operation of said relay for transmitting a signal identifying said line.

28. In a combined telephone and signalling system, an exchange, a plurality of subscribers lines extending to said exchange, a telephone including an impulsing device connected to one of said lines, an automatic switch adapted to be taken for use by said one line in response to the initiation of a call at said telephone, said switch being operable to a plurality of positions in response to impulses transmitted thereto from said impulsing device, holding means operative in response to the operation of said switch to a predetermined position, a relay associated with said one line, a normally open operating circuit for said relay, means comprising said holding means for completing said circuit, a normally open holding circuit for said relay, signalling means responsive to the operation of said relay for transmitting a signal identifying said one line, and means included in said signalling means for completing said holding circuit, whereby said signal is completely transmitted irrespective of the condition of said holding means.

CLARENCE E. LOMAX. JOHN H. VOSS. 

